A touchscreen is an input and output device usually layered on the top of an electronic visual display. A user can enter input or control an information processing system by touching the screen with one or more fingers, a stylus or a special pen to substitute for (or use instead of) a mouse or a remote control. The touchscreen enables the user to interact directly with what is displayed, rather than using a mouse, a keyboard, or other such devices (other than a stylus, which is optional for most modern touchscreens). With easily-marketed features of easy portability, use and control, which is especially important for elder users and children, the touchscreen provides high convenience and has become a main product in the consumer display market.